Large angle grinder

ABSTRACT

An angle grinder is provided including a radial fan assembly. The radial fan assembly is configured to direct exhaust radially outwardly and axially away from a user of the angle grinder. Brush card assemblies for an angle grinder are also provided. The brush card assemblies provide for the securing of brush cards to a field case of the angle grinder by the interface between the field case and brush cards. Additionally, a spindle lock mechanism and a safety mechanism for an angle grinder are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/549,264 filed on Oct. 13, 2006. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present disclosure generally relates to angle grinders, andgenerally describes various features of a large angle grinder (LAG). Itwill be appreciated, however, that other angle grinders are known in theart, including medium angle grinders (MAG) and small angle grinders(SAG). Therefore, it will be further appreciated that each of the hereindescribed features may be readily adapted for use with a LAG, MAG,and/or SAG as well as other power tools.

BACKGROUND AND SUMMARY

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Angle grinding tools are commonly used for grinding and sandingapplications. Angle grinders include a rotary shaft such as a wheelspindle for driving a grinding wheel mounted thereon. The presentapplication describes several improvements for angle grinders.

The present disclosure provides a radial fan assembly for a large anglegrinder. The radial fan assembly directs exhaust radially outwardly andaxially away from a user of the large angle grinder. The radial fanassembly can provide for efficient operation of the tool.

The present disclosure further provides brush card assemblies for alarge angle grinder. The brush card assemblies include brush cards andare secured by an interface between the brush cards and the toolhousing. Therefore, the brush card assemblies can provide for simpleassembly of the tool.

Additionally, the present disclosure provides for an improved and costefficient spindle lock mechanism and safety mechanism. The spindle lockmechanism of the present disclosure is configured to experiencerelatively low stress and avoid coast-down engagement. The safetymechanism of the present disclosure can be separate from an operatingswitch of the tool and thus is cost efficient.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a perspective view of a large angle grinder according to theprinciples of the present disclosure;

FIG. 2 is a side view of a large angle grinder according to theprinciples of the present disclosure with a partial cutaway view;

FIG. 3 is an exploded perspective view of a radial fan assembly of alarge angle grinder according to the principles of the presentdisclosure;

FIG. 4 is a perspective view of a fan component of a radial fan assemblyfor a large angle grinder according to the principles of the presentdisclosure;

FIG. 5 is another perspective view of the fan component of FIG. 4;

FIG. 6 is a perspective view of a baffle component of a radial fanassembly for a large angle grinder according to the principles of thepresent disclosure;

FIG. 7 is a perspective view of a portion of the baffle component ofFIG. 6;

FIG. 8 is a front view of the portion of the baffle component of FIG. 7;

FIG. 9 is a perspective view of a portion of a gear case for a largeangle grinder according to the principles of the present disclosure;

FIG. 10 is a perspective view of a vent feature portion of the gear caseof FIG. 9;

FIG. 11 is a cross sectional view of a portion of a radial fan assemblyaccording to the principles of the present disclosure;

FIG. 12 is a perspective view of a portion of a radial fan assemblyaccording to the principles of the present disclosure;

FIG. 13 is a top view of a portion of a large angle grinder according tothe principles of the present disclosure;

FIG. 14 is an end view of a large angle grinder according to theprinciples of the present disclosure;

FIG. 15 is a side view of a brush card assembly for a large anglegrinder according to the principles of the present disclosure;

FIG. 16 is a perspective view of a brush card and associated componentsfor a large angle grinder according to the principles of the presentdisclosure;

FIG. 17 is an end view of the brush card and associated components ofFIG. 16;

FIG. 18 is a side view of the brush card and associated components ofFIG. 16;

FIG. 19 is a bottom view of the brush card and associated components ofFIG. 16;

FIG. 20 is a perspective view of the brush card assembly of FIG. 15;

FIG. 21 is a perspective view of a field case for a large angle grinderaccording to the principles of the present disclosure;

FIG. 22 is a cross sectional view of a portion of the brush cardassembly of FIG. 15;

FIG. 23 is a perspective view of another brush card and associatedcomponents according to the principles of the present disclosure;

FIG. 24 is another perspective view of the brush card and associatedcomponents of FIG. 23;

FIG. 25 is a perspective view of another brush card assembly accordingto the principles of the present disclosure;

FIG. 26 is a perspective view of another field case according to theprinciples of the present disclosure;

FIG. 27 is front view of a portion of the brush card assembly of FIG.25;

FIG. 28 is side view of a portion of the brush card assembly of FIG. 25;

FIG. 29 is cross sectional view of a front portion of a large anglegrinder including a spindle lock assembly according to the principles ofthe present disclosure;

FIG. 30 is a partial cross sectional view of the spindle lock assemblyof FIG. 29 in a disengaged position;

FIG. 31 is a partial cross sectional view of the spindle lock assemblyof FIG. 29 in an engaged position;

FIG. 32 is a cross sectional view of a handle portion of a large anglegrinder including a disengaged safety switch and trigger assemblyaccording to the principles of the present disclosure;

FIG. 33 is a cross sectional view of the handle portion of FIG. 32including an engaged safety switch and a disengaged trigger assembly;and

FIG. 34 is cross sectional view of the handle portion of FIG. 32including an engaged safety switch and trigger assembly.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.For example, like elements may be referred to by the reference indicia75 and 75′. Additionally, as used herein, the terms “axial” and“axially” refer to a direction substantially parallel to an axis ofrotation of a shaft according to the principles of the presentdisclosure. Furthermore, as used herein, the terms “radial” and“radially” refer to directions substantially perpendicular to an axis ofa shaft according to the principles of the present disclosure.

According to the principles of the present disclosure, an angle grinderis provided including a radial fan assembly. The radial fan assembly isconfigured to direct exhaust radially outwardly and axially away from auser of the angle grinder. Brush card assemblies for an angle grinderare also provided. The brush card assemblies provide for the securing ofbrush cards to a field case of the angle grinder by the interfacebetween the field case and brush cards. Additionally, a spindle lockmechanism and a safety mechanism for an angle grinder are provided.

Referring to FIGS. 1-2, a large angle grinder (LAG) 100 can include ahousing 112 having a handle portion 114, a field case 116 and a gearcase 118. Field case 116 can have a first end 120 and a second end 122.Handle portion 114 can be formed proximate first end 120, and gear case118 can be fixedly attached proximate second end 122. Field case 116 cansupport a motor 124 therein for powering LAG 100.

LAG 100 can include a switch mechanism 126, a safety mechanism 128, andassociated components therewith mounted in handle portion 114. LAG 100can also include a wheel spindle 129 (FIG. 2) extending from gear case118. Furthermore, LAG 100 can include a grinder wheel 130 selectivelyattachable to wheel spindle 129 and a wheel guard 132 coupled to gearcase 118. Wheel spindle 129 and grinder wheel 130 can be operablycoupled to motor 124 for powering rotation thereof during operation ofLAG 100. Additionally, LAG 100 can include an adjustable handlecomponent 134 attached to gear case 118. Handle component 134 can beselectively configured by an operator of LAG 100.

Radial Fan

With further reference to FIGS. 3-14, LAG 100 can include a radial fanassembly 150 disposed between field case 116 and gear case 118. Radialfan assembly 150 can include exhaust vents 152 a-d (FIGS. 1, 14)disposed around LAG 100. In particular, radial fan assembly 150 caninclude fan exhaust vents 152 a, 152 b, 152 c, 152 d (FIG. 14). Asdescribed in more detail below, radial fan assembly 150 can operate todraw air in intake vents 154 disposed at the first end 120 of field case116 (FIG. 1) and exhaust the air out of exhaust vents 152 a-d.

Radial fan assembly 150 can include a fan component 156, a bafflecomponent 158, and gear case 118. Fan component 156 can be coupledbetween baffle component 158 and gear case 118 and can be operablycoupled to the motor for powering rotation thereof. Baffle component 158can be directly coupled to field case 116.

Referring in particular to FIGS. 4-5, fan component 156 can have a backplate 159 including a first side 160 (FIG. 4) and a second side 162(FIG. 5). Fan component 156 can be positioned with first side 160 facingfield case 116 and second side 162 facing gear case 118, as illustratedin FIG. 3. Back plate 159 can be sized to effectively seal gear case 118from radial fan assembly 150 and field case 116 to inhibit aircirculation therebetween. Such a configuration can help prevent unwantedpressurization of gear case 118 and back pressure on radial fan assembly150.

Back plate 159 can include a plurality of blades 164 extending axiallyoutwardly from first side 160. Blades 164 can be configured to draw airthrough field case 116 toward first side 160 and direct the air radiallyfrom fan component 156 when fan component 156 rotates. Furthermore,blades 164 can be configured so that back plate 159 defines an outsidearea 166 on first side 160 between radially outward ends 168 of blades164 and a perimeter 170 thereof.

Back plate 159 can further include ribs 172, 174, 176 extending axiallyoutwardly from second side 162. Ribs 172, 174 can have radially inwardpositions on second side 162. Rib 176 can have a radially outwardposition on second side 162 proximate perimeter 170 of back plate 159.As a user of LAG 100 would see blades 164, outside area 166, perimeter170, and rib 176 when looking into exhaust vents 152 a-d (see, forexample, exhaust vent 152 a in FIG. 12), these features can provide avisually clean interior surface of LAG 100.

Referring in particular to FIGS. 6-8, baffle component 158 can have agenerally annular shape including a main ring 180. Ring 180 can have acentral aperture 182 formed therein and can define a perimeter 184 alongthe outside thereof. Aperture 182 can provide for fluid communicationbetween field case 116 and first side 160 of fan component 156 throughaperture 182. Furthermore, ring 180 can define first and second sides186, 188. Baffle component 158 can be disposed with first side 186facing field case 116 and second side 188 facing fan component 156 (FIG.3).

Baffle component 158 can further include vent features 190 a-d extendingradially outwardly from ring 180 at perimeter 184. Baffle component 158can include four vent features 190 a, 190 b, 190 c, 190 d evenly spacedaround perimeter 184. As described in further detail below, ventfeatures 190 a-d can, in combination with gear case 118, form exhaustvents 152 a-d.

Vent feature 190 a will be described in further detail herein. As ventfeatures 190 b, 190 c, 190 d can include features corresponding to ventfeature 190 a, it is to be understood that the description of ventfeature 190 a can apply to vent features 190 b, 190 c, and 190 d.

Vent feature 190 a can be integrally formed with ring 180. Vent feature190 a can have an impact rib 191 a formed on a radially outward portionthereof. Furthermore, vent feature 190 a can include a plurality ofsurfaces. In particular, vent feature 190 a can include a main surface192 a extending radially from ring 180 along perimeter 184. Main surface192 a can be axially sloped away from first side 186 of ring 180. Ventfeature 190 a can further include first and second side surfaces 200 a,202 a. First side surface 200 a can extend axially from an end of mainsurface 192 a and can be sloped relative to a radial direction towardmain surface 192 a so as to face in a direction that is, in part,radially outward. First side surface 200 a can further include a roundedportion 206 a proximate perimeter 184. Second side surface 202 a canextend axially from an opposite end of main surface 192 a and can besloped relative to a radial direction away from main surface 192 a so asto face in a direction that is, in part, radially inward. Second sidesurface 202 a can further include a rounded portion 210 a proximateperimeter 184.

Referring in particular to FIGS. 9-10, gear case 118 can include a mainpart 220 and an end part 222. Main part 220 can be configured to couplegear case 118 to the field case 116. End part 222 can extend axiallyfrom main part 220 and can be configured to support wheel spindle 129and grinder wheel 130 (FIG. 1) and associated components, as describedin more detail below.

Main part 220 can include vent features 230 a-d formed therein. Fourvent features 230 a, 230 b, 230 c, 230 d can be evenly spaced aroundmain part 220. As described in further detail below, vent features 230a-d can, in combination with vent features 190 a-d of baffle component158, form exhaust vents 152 a-d.

Vent feature 230 a will be described in further detail herein. As ventfeatures 230 b, 230 c, 230 d can include features corresponding to ventfeature 230 a, it is to be understood that the description of ventfeature 230 a herein can apply to vent features 230 b, 230 c, and 230 d.

Vent feature 230 a can be integrally formed with main part 220. Ventfeature 230 a can have an impact rib 231 a formed on a radially outwardportion thereof. Impact rib 231 a can have a complementary shape andposition with respect to impact rib 191 a. Impact ribs 191 a, 231 a canprotect exhaust vent 152 a from a drop or other impact. Furthermore,vent feature 230 a can have a plurality of surfaces. Vent feature 230 acan have a main surface 232 a extending radially from main part 220.Main surface 232 a can be axially sloped toward end part 222. Ventfeature 230 a can further include first and second side surfaces 240 a,242 a. First side surface 240 a can extend axially from an end of mainsurface 232 a, and second side surface 242 a can extend axially from anopposite end of main surface 232 a. Vent feature 230 a can also includefirst and second fillet portions 244 a, 246 a between main surface 232 aand first and second side surfaces 240 a, 242 a, respectively, and athird fillet portion 248 a between main surface 232 a and main part 220.

Main part 220 can also include projections 260 (FIG. 11) formed therein.Projections 260 can have a complementary shape and position with respectto ribs 172, 174, 176 of fan component 156.

Referring in particular to FIGS. 11-14, radial fan assembly 150 canoperate to draw air through field case 116 and expel the air(represented in the Figures by the arrows labeled “A”) out exhaust vents152 a-d. When fan component 156 rotates, blades 164 operate to draw airtowards first side 160 of back plate 159. As fan component 156 isconfigured to be a radial fan, the air is exhausted radially outwardlyat ends 168 of blades 164. The air is then directed axially away fromhandle portion 114 of LAG 100, thus axially away from a user of LAG 100,by baffle vent features 190 a-d. Gear case vent features 230 a-d, havinga complementary shape to baffle vent features 190 a-d, allow the air tobe directed axially away as well as help direct the air. As shown inFIGS. 13 and 14, exhaust vents 152 a-d can direct the air approximately45° from the radial direction and approximately 20° from a directiontangent to the outer diameter of fan component 156.

Exhaust vents 152 a-d are configured to allow as much air as possibletherethrough. In particular, baffle vent features 190 a-d include slopedside surfaces 200 a-d, 202 a-d which correspond to the radial path ofthe exhausted air. Accordingly, baffle vent features 190 a-d can allowfor a large air flow therethrough. Additionally, fan component 156 canbe positioned relative to gear case 118 so that first side 160 of backplate 159 is closer to handle portion 114. Therefore, radial fanassembly 150 can operate with a relatively high efficiency, as there isminimum recirculation and high and low pressure zones can be preventedfrom forming and causing degradation in performance.

Furthermore, according to the principles of the present disclosure,various features of radial fan assembly 150 inhibit whistling noise frombeing produced during operation. The production of whistling noise byblades 164 can be reduced by providing a radial gap between radiallyoutward ends 168 of blades 164 and any other component of radial fanassembly 150 and LAG 100, the gap being sized approximately 7-8% of thediameter of back plate 159. Such a gap can be provided by outside area166 on first side 160 of back plate 159 or otherwise by theconfiguration of radial fan assembly 150. Furthermore, rounded positions206 of baffle vent features 190 a-d and the fillet portions of gear casevent features 230 a-d can inhibit production of whistling noise at thesepositions. Additionally, as fan component 156 is positioned with firstside 160 of back plate 159 away from gear case 118, the production ofwhistling noise between fan component 156 and gear case vent features230 a-d can be reduced.

Additionally, ribs 172, 174, 176 of fan component 156 and complementaryprojections 260 on main part 220 of gear case 118 can inhibit dust andother particles from traveling proximate first side 160 of fan component156 from gear case 118 and being expelled out exhaust vents 152 a-d.When radial fan assembly 150 is assembled, these features can overlapand create an undulating path therebetween. As the circulation of airwith gear case 118 is inhibited as described above, it can be difficultfor dust and other particles to navigate such an undulating path.

According to the principles of the present disclosure, a radial fanassembly can vary in many ways. A radial fan assembly can include avariety of components including but not limited to those disclosedherein. The components of a radial fan assembly according to theprinciples of the present disclosure can have a variety ofconfigurations. It is to be understood that the components are notlimited to the exemplary configurations disclosed in detail herein.Furthermore, the components of a radial fan assembly according to theprinciples of the present disclosure can each include a variety ofrelatively rigid materials as is well understood in the art.

Brush Card Assembly

As described in detail below, LAG 100 can include a brush card assembly270 for supporting a motor brush 272 (FIGS. 15-20) proximate motor 124.Accordingly, details of motor 124 are first discussed.

Motor 124 can be a universal series motor of a type commonly known inthe art. With particular reference to FIG. 2, motor 124 generallyincludes a motor spindle 280, a motor armature 282, a field pole 284,field windings 286, and a commutator 288. As is described in furtherdetail below, electrical leads (not shown) can be included for linkingmotor brush 272 to switch mechanism 126 for selective connection with apower source (not shown).

Field case 116 can have a generally cylindrical shape supporting fieldpole 284. Field windings 286 are formed from repetitive windings of wiredisposed on either side of field pole 284. Power from the power sourceruns through a portion of field windings 286 creating an electric fieldfor causing rotation of motor armature 282.

Motor armature 282 can be fixed for rotation with motor spindle 280.Motor spindle 280 is supported by a bearing (not shown) proximate firstend 120 of field case 116, through commutator 288. Another bearing (notshown) seats within gear case 118 for supporting an opposite end of themotor spindle 280.

Commutator 288 is fixed for rotation with motor spindle 280 and providesan electrical connection between the rotating motor armature 282 andstationary motor brush 272. Generally, the stationary motor brush 272 isheld in contact with commutator 288 by spring tension (as will bediscussed in detail hereinbelow). Motor brush 272 completes theelectrical link between the rotating commutator 288, motor armature 282,and switch mechanism 126.

Referring to FIGS. 15-22, LAG 100 can include brush card assembly 270.Brush card assembly 270 can include a brush card 310 configured toengage with field case 116. As shown in FIG. 16, brush card 310 cansupport a variety of components including a mounting plate 312 directlycoupled to brush card 310, and a brush spring 314 and a brush box 316attached to mounting plate 312. Motor brush 272 can be disposed withinbrush box 316. These components interact with motor 124 during operationof LAG 100. For example, brush spring 314 can bias motor brush 272 incontact with commutator 288.

As shown in FIG. 19, brush card 310 can further include an aperture 330therethrough proximate brush box 316 and motor brush 272. Additionally,as shown in FIG. 17, brush box 316 can include radially inwardlyextending rounded projections 332 which contact motor brush 272 andprovide spaces 334 between brush box 316 and motor brush 272. Aperture330 and spaces 334 can provide for cooling of the components and canhelp inhibit particle buildup during operation of LAG 100 and,therefore, can help improve the efficiency of LAG 100.

Referring in particular to FIGS. 16-19, brush card 310 can have agenerally rectangular shape including a first or top surface 350, asecond or bottom surface 352, and outside surface 354 extendingtherebetween. Top and bottom surfaces 350, 352 can include a variety offeatures for coupling the components of brush card assembly 270discussed above. Furthermore, surfaces 350, 352, 354 can includefeatures facilitating the engagement and securing of brush card 310 andfield case 116, as described in more detail below.

Outside surface 354 can include sides 360, more particularly opposingsides 360 a, 360 b. Side 360 a can include a first sloped portion 370 aand a recess 372 a. First sloped portion can extend from a corner ofoutside surface 354 along side 360 a. Recess 372 a can be adjacent firstsloped portion 370 a and can further include second sloped portion 374a. Second sloped portion 374 a can be sloped in the opposite directionrelative to first sloped portion 370 a. Side 360 b can include featurescorresponding to side 360 a and, therefore, will not be described infurther detail herein. Additionally, brush card 310 can includeprojections 380 extending outwardly therefrom proximate opposing sides360 a, 360 b.

Brush card assembly 270 can also include field case 116. Referring inparticular to FIGS. 15 and 20-21, field case 116 can have a generallycylindrical shape and can include a main body 400. Main body 400 canhave an aperture 402 defined therein between an outside surface 404 andan inside surface 406 thereof. Aperture 402 can be configured to allowassembly of brush card 310 and associated components therethrough.

Main body 400 can also include a pair of guides 410 a, 410 b extendingfrom inside surface 406 proximate aperture 402. Guide 410 a can belocated on a predetermined position of main body 400 and can includefirst and second elongate support segments 420 a, 422 a and a connectingsegment 424 a extending therebetween, as shown in FIG. 21. Supportsegments 420 a, 422 a and connecting segment 424 a can be integrallyformed with main body 400. First ends 426 a, 428 a of support segments420 a, 422 a respectively can be disposed proximate aperture 402.Connecting segment 424 a can extend between second ends 430 a, 432 a ofsupport segments 420 a, 422 a opposite first ends 426 a, 428 a. Supportsegments 420 a, 422 a can extend parallel to each other and in adirection perpendicular to an axial direction. Guide 410 b can includefeatures corresponding to guide 410 a and, therefore, will not bedescribed in further detail herein.

Brush card 310 and field case 116 can engage with each other to formbrush card assembly 270 and, thereby, secure brush card 310 to fieldcase 116. In particular, the interface between guides 410, sides 360,and projections 380 can provide for the engagement and securing of brushcard 310 and field case 116. Sides 360 of brush card 310 can be disposedbetween support segments 420, 422 of guides 410. First sloped surfacesof sides 360, 362 can engage connecting segments 424, and main body 400of field case 116 can elastically deform in correspondence with suchengagement. Brush card 310 can be inserted into main body 400 relativeto guides 410, 412 until the recesses of sides 360, 362 engage with theconnecting segments and main body 400 returns to its original shape.Projections 380 of brush card 310 can engage with the support segmentsand can position brush card 310 relative to the support segments.Additionally, the second sloped surfaces of sides 360, 362 can biasbrush card 310 into maintaining engagement with guides 410, 412.

Referring to FIGS. 23-28, an alternately configured brush card assembly270′ can include a brush card 310′. Brush card 310′ can have a mountingplate 312′ attached thereto, and mounting plate 312′ can support a brushspring 314′ and a brush box 316′. Brush box 316′ can support a motorbrush (not shown).

Brush card 310′ can have a generally rectangular shape. Brush card 310′can include a first or top surface 350′ or a second or bottom surface352′. Furthermore, brush card 310′ can include an outside surface 354′defined between top and bottom surfaces 350′, 352′. As shown in FIGS.23-28, a portion of outside surface 354′ can have a curved shape.

Brush card assembly 270′ can further include a field case 116′. Fieldcase 116′ can have a main body 400′. Main body 400′ can have an aperture402′ therein and can define an outside surface 404′ and an insidesurface 406′. Aperture 402′ can be configured to receive brush card 310′and the components associated therewith.

Main body 400′ of field case 116′ can also include a pair of frontcoupling arms 450′ and a pair of side coupling arms 452′ extending frominside surface 406′. Front coupling arms 450′ can include main portions460′, flange portions 462′ extending inwardly from main portions 460′,and sloped portions 464′ extending between main portions 460′ and flangeportions 462′. Similarly, side coupling arms 452′ can include mainportions 470′, flange portions 472′ extending inwardly from mainportions 470′, and sloped portions 474′ extending between main portions470′ and flange portions 472′. Additionally, side coupling arms 452′ canhave connecting portions 476′ extending inwardly from inside surface406′ of main body 400′, and sloped portions 474′ can further extendbetween main portions 470′ and connecting portions 476′.

Furthermore, main body 400′ of field case 116′ can include supports 480′extending inwardly from inside surface 406′ proximate aperture 402′. Asshown in the Figures, main body 400′ can include three supports 480′. Itshould be understood that, according to the principles of the presentdisclosure, main body 400′ can include two or more supports 480′.Supports 480′ can have top surfaces 482′ extending complementarily toeach other. Top surfaces 482′ can have recess features 484′ definedtherein.

Brush card 310′ can engage main body 400′ of field case 116′ to formbrush card assembly 270′. The interface between brush card 310′ andfield case 116′ can secure brush card 310′ and field case 116′. Brushcard 310′ can be inserted into aperture 402′ of main body 400′ and canengage with sloped portions 464′, 474′ of coupling arms 450′, 452′.Referring in particular to FIGS. 27 and 28, coupling arms 450′, 452′ canelastically deform to allow brush card 310′ to engage with main body400′. Specifically, coupling arms 450′, 452′ can deflect outwardly whenoutside surface 354′ of brush card 310′ engages sloped portions 464′,474′. Coupling arms 450′, 452′ can return to their original positionswhen outside surface 354′ of brush card 310′ engages main portions 460′,470′ and top surface 350′ engages flange portions 462′, 472′.Furthermore, bottom surface 352′ of brush card 310′ can engage with topsurfaces 482′ of supports of 480′. Specifically, bottom surface 352′ ofbrush card 310′ can have complementary features to recess features 484′.Accordingly, the interface of brush card 310′ and main body 400′ cansecure brush card 310′ to field case 116′.

A brush card assembly according to the principles of the presentdisclosure can vary in a number of ways. Brush cards according to thepresent disclosure can have a variety of configurations not limited tothose disclosed therein. Field cases according to the present disclosurecan have a variety of configurations not limited to those disclosedherein. For example, field cases can include a varied number of guidesand coupling arm features. Furthermore, guide features and coupling armfeatures of field cases can have a variety of shapes and configurations.These features can also be positioned in a number of ways. Components ofbrush card assemblies according to the present disclosure can be made ofa variety of relatively rigid materials well-known in the art.

It is to be understood that large angle grinders and other power toolsaccording to the principles of the present disclosure can include brushcard assemblies which have more than one brush card and associated motorbrush. Specifically, a brush card assembly according to the principlesof the present disclosure can have two brush cards and two associatedmotor brushes therewith on opposite sides of a motor. It should beunderstood that the features described herein with regard to individualbrush card assemblies can apply to brush card assemblies having multiplebrush cards and motor brushes.

Spindle Lock

LAG 100 can include a spindle lock mechanism 500 for inhibiting rotationof motor spindle 280 and associated components to enable grinder wheel130 or another attachment to be removed and/or replaced. As such,components associated with grinder wheel 130 and motor spindle 280 willbe first discussed.

LAG 100 can include a gearset 510 disposed within gear case 118 fortranslating rotational motion of motor spindle 280 to wheel spindle 129.Wheel spindle 129 extends generally perpendicular to motor spindle 280.Gearset 510 generally includes a pinion gear 512 and a main gear 514.Pinion gear 512 is fixed for rotation with motor spindle 280, which isrotatably driven by motor 124. Main gear 514 is fixed for rotation withwheel spindle 129 and is driven by pinion gear 512. Typically, main gear514 is in the form of a bevel gear, and pinion gear 512 has a generallyfrusto-conical shape.

Both pinion gear 512 and main gear 514 can be sized according to adesired amount of torque transmission and a desired gear ratio. Thehigher the torque transmission that is required, the larger gearset 510must be, specifically, pinion gear 512. To reduce overall manufacturingcosts, tool weight and tool efficiency, it is desirable to provide agearset 510 that is minimal in size and weight while maximizing theamount of torque transmittable therethrough.

As previously discussed, grinder wheel 130 is selectively fixed forrotation with wheel spindle 129. As shown in FIG. 2, grinder wheel 130is received onto wheel spindle 129 and may be secured thereto by a nut520. Grinder wheel 130 may be removed for several reasons, including LAG100 maintenance, replacement of a broken or worn grinder wheel 130, orexchanging the type of grinder wheel 130 used (e.g. fine, coarse). Wheelguard 132 is attachable to gear case 118 for protecting an operator fromthe spinning grinder wheel 130. Wheel guard 132 covers an arcuralportion of grinder wheel 130 and is adjustable about grinder wheel 130.Additionally, grinder wheel 130 sizes may vary and therefore each sizecan require a corresponding wheel guard 132.

Referring to FIGS. 29-31, LAG 100 can include spindle lock mechanism 500to inhibit the rotation of motor spindle 280 and wheel spindle 129 sothat grinder wheel 130 can be removed and replaced. Spindle lockmechanism 500 can include a pin 540. Spindle lock mechanism 500 can alsoinclude a projection 542 extending outwardly from gear case 118.Projection 542 can be integrally formed with gear case 118 with anaperture 544 extending therethrough. Spindle lock mechanism 500 can alsoinclude an inner flange 546 of gear case 118 with an aperture 548therethrough. Pin 540 can extend between projection 542 and inner flange546 through apertures 544, 548. Furthermore, spindle lock mechanism 500can include a biasing member 550 disposed around pin 540 betweenprojection 542 and inner flange 546. Biasing member can engage a flange552 of pin 540 as well as opposing surfaces of projection 542 and innerflange 546. Spindle lock mechanism 500 can also have a button component554 disposed on an end of pin 540 outside of gear case 118 configured tobe engaged by a user of LAG 100. Additionally, spindle lock mechanism500 include pinion gear 512, which can have an aperture 560 definedtherein. Aperture 560 can be configured to receive pin 540. Furthermore,pinion gear 512 can be configured to have an elliptical cross section,such as shown FIGS. 30 and 31.

Spindle lock mechanism 500 is normally at a disengaged position, shownin FIGS. 29 and 30. In the disengaged position, biasing member 550positions pin 540 away from pinion gear 512. Accordingly, pinion gear512 can rotate, and motor 124 can transfer rotational motion to grinderwheel 130 through motor spindle 280, main gear 514 and wheel spindle129. With an elliptical cross section, pinion gear 512 can help preventundesired engagement of pin 540 and aperture 560 during rotation ofpinion gear 512, as the wider ends of pinion gear 512 can deflect pin540 away before it can engage aperture 560.

When pinion gear 512 is not rotating, spindle lock mechanism 500 can beoperated to engage pin 540 with aperture 560, as shown in FIG. 31. Tooperate spindle lock mechanism 500, a user of LAG 100 depresses buttoncomponent 554 and forces pin 540 into engagement with aperture 560. Suchengagement prevents rotation of pinion gear 512 and, thus, operation ofLAG 100. Accordingly, grinder wheel 130 can be safely removed andreplaced from wheel spindle 129. When grinder wheel 130 has beenreplaced the user of LAG 100 can release button component 554 andbiasing number 550 automatically returns pin 540 to a disengagedposition. LAG 100 is in condition for operation.

As spindle lock mechanism 500 engages the pinion gear 512 of LAG 100 inorder to operate, spindle lock mechanism 500 can be more robust thanother such assemblies. Engagement with pinion gear 512 allows for lessstress on pin 540 due to gear reduction the gear set 510. Furthermorethe features of spindle lock mechanism 500, such as the shape of piniongear 512, can help prevent coast down engagement of pin 540 and piniongear 512.

The components of spindle lock mechanism 500 can be made from a varietyof relatively rigid materials well known in the art. Furthermore, theconfiguration of spindle lock mechanism 500 and the individualcomponents thereof can vary according to the principles of the presentdisclosure. As such, spindle lock mechanism 500 and the individualcomponents thereof should be understood as not being limited to theembodiments disclosed herein.

Safety Mechanism

Referring to FIGS. 1-2 and 32-34, LAG 100 can include a safety mechanism128. Safety mechanism 128 can inhibit unintended operation of LAG 100 bymechanical interaction with switch mechanism 126. According to theprinciples of the present disclosure, safety mechanism 128 is separateand independent from switch mechanism 126 and can be adapted to workwith a variety of conventional switches. Therefore, safety mechanism 128can provide for cost effective production of LAG 100 such as bysimplified design and manufacturing.

As described above, exemplary switch mechanism 126 is operable toselectively supply power to motor 124. Switch mechanism 126 is inelectrical communication with motor 124 as well as a power source (notshown, via a cord 590 shown in FIG. 2). Handle portion 114 preferablyincludes an opening 592 (FIG. 2) opposite field case 116 through whichcord 590 runs.

Switch mechanism 126 can include a trigger or main portion 600 pivotablysupported at a pivot point 602. Main portion 600 is normally away fromhandle portion 114 in an OFF position (FIGS. 32-33). Depression of mainportion 600 toward handle portion 114 locates main portion 600 in an ONposition (FIG. 34) and initiates operation of LAG 100. Switch mechanism126 can include a variety of additional components coupled to mainportion 600 within handle 114. For example, a lever 604 is coupled tomain portion 600 and moves along handle 114 according to the position ofmain portion 600.

However, as shown in FIG. 32, safety mechanism 128 can have a maincomponent 610 blocking the movement of lever 604 and, therefore, theoperation of switch mechanism 126. Thus, in order to locate main portion600 to the ON position, safety mechanism 128 must be operated.

Safety mechanism 128 can be disposed in handle portion 114 proximateswitch mechanism 126. Main component 610 of safety mechanism 128 canhave a button portion 612. Button portion 612 includes first and secondsurfaces 614, 616 and an outside surface 618 extending therebetween.Button portion 612 further includes a lip 620 extending outwardly fromoutside surface 618 proximate second surface 616. A top surface 622 oflip 620 is defined opposite second surface 616. Main component 610further includes a finger 630 extending from second surface 616. Finger630 has a protrusion 632 extending therefrom. Protrusion 632 has a firstsurface 634 on an outer part thereof and a second surface 636 betweenfinger 630 and first surface 634.

Main component 610 of safety mechanism 128 is received by an innerfeature 640 of handle portion 114. Inner feature 640 includes a mainsurface 642 and a lip engagement surface 644. Furthermore, inner feature640 has an aperture 646 through which finger 630 can extend.

Safety mechanism 128 further includes a spring 650 coupled between maincomponent 610 and inner feature 640. In particular, spring 650 engagessecond surface 616 of button portion 612 and main surface 642 of innerfeature 640.

As noted above, safety mechanism 128 must be depressed in order to allowswitch mechanism 126 to be operated. Safety mechanism 128 is normally inan undepressed position (FIG. 32). Spring 650 biases main component 610outwardly until top surface 622 of lip 620 engages lip engagementsurface 644 of inner feature 640. Main component 610 is configured sothat in this position first surface 634 of protrusion 632 engages lever604. This engagement prevents operation of LAG 100 by creating amechanical lock that inhibits movement of lever 604 and thus rotation ofmain portion 600 of switch mechanism 126.

When main component of 610 of safety mechanism 128 is depressed, buttonportion 612 main component 610 moves along inner feature 640 (FIG. 33).Second surface 616 of button portion 612 engages main surface 642 ofinner feature 640. Furthermore, protrusion 632 moves to a position wherefirst surface 634 is not engaged with lever 604.

With main component 610 and lever 604 disengaged, main portion 600 ofswitch mechanism 126 can be depressed. Depression of main portion 600rotates main portion 600 about pivot point 602 and moves lever 604adjacent second surface 636 of protrusion 632 of main component 610(FIG. 34). As such, lever 604 holds safety mechanism 128 in thedepressed position while main portion 600 remains depressed and switchmechanism 126 in the ON position. When switch mechanism 126 is releasedto the OFF position, spring 650 can automatically bias safety mechanismback to the undepressed position.

Switch mechanism 126 can further include a lock-on button 664 (FIG. 1).Lock-on button 664 can be engaged when switch mechanism 126 is in the ONposition to maintain the position.

The components of switch mechanism 126 and safety mechanism 128 can bemade from a variety of relatively rigid materials well known in the art.Furthermore, the configurations of the individual components of switchmechanism 126 and safety mechanism 128 can vary according to theprinciples of the present disclosure. As such, switch mechanism 126,safety mechanism 128, and the individual components thereof should beunderstood as not being limited to the embodiments disclosed herein.

It should be understood that this disclosure is exemplary in nature, andthat the principles of the present disclosure are can apply to a varietyof angle grinders and other power tools. As such, this disclosure is notlimited to the specific embodiments disclosed herein. For example, itshould be understood that an angle grinder or other power tool caninclude one or more of the radial fan assembly, brush card assemblies,spindle lock, and safety switch disclosed herein.

1. An angle grinder comprising: a field case having a handle disposed atan end thereof; a motor disposed within said field case, said motorhaving a spindle extending axially therefrom, said motor spindle havinga pinion gear fixed to an end thereof for rotation with said motorspindle; a gear case coupled to an end of said field case opposite saidhandle, said gear case including a wheel spindle extending therefrom,said wheel spindle being operably coupled to said pinion gear and beingadapted to receive an attachment for the angle grinder for rotationtherewith; and a lock mechanism supported by said gear case, said lockmechanism being selectively operable to engage said pinion gear andinhibit rotation of said wheel spindle.
 2. The angle grinder of claim 1,wherein said lock mechanism includes a pin coupled to said gear case, abutton coupled to an end of said pin outside of said gear case, and abiasing member disposed between said pin and said gear case, and whereinsaid pinion gear includes an aperture therein adapted to receive saidpin.
 3. The angle grinder of claim 1, wherein said biasing memberlocates said pin in a disengaged position relative to said pinion gear,and said button is selectively operable to locate said pin in saidaperture and in engagement with said pinion gear to inhibit rotation ofsaid wheel spindle.
 4. The angle grinder of claim 1, wherein saidbiasing member is a spring.
 5. The angle grinder of claim 1, whereinsaid pinion gear has an elliptical cross section.